#include<iostream>
#include<vector>

using namespace std;

int main(){
	int n;
	cin>>n;
	vector<int> nums(n);
	for(int i=0;i<n;i++){
		cin>>nums[i];
	}

	vector<vector<int>> dp(n + 2, vector<int>(n + 2));
    vector<int> val(n + 2);
    
    val[0] = val[n + 1] = 1;
    for (int i = 1; i <= n; i++) {
        val[i] = nums[i - 1];
    }
    
	for (int i = n - 1; i >= 0; i--) {
        for (int j = i + 2; j <= n + 1; j++) {
            for (int k = i + 1; k < j; k++) {
                int sum = val[i] * val[k] * val[j];
                sum += dp[i][k] + dp[k][j];
                dp[i][j] = max(dp[i][j], sum);
            }
        }
    }
    
    cout<<dp[0][n + 1]<<endl;
    return 0;
} 
